'58 CJ3B Intermittant Missfire

[aboyandhisdog]

It sounds like you are trying to keep everything stock, but at the risk of being shunned from the 3A page, I will admit that I do like my Omix electronic diz very much.  It is going strong after 11 years.  I did have to swap in a new module once, but that was "operator failure" on my part.  And a new module is about $59 so I always carry a spare in my parts bag just like guys will carry points and condenser.  I could not be happier with this dizzy.

[SteveKfl]

I can't imagine the wear that fast, so I'm guessing maybe the plate the points are mounted on is moving.  Could that be because of the vacuum advance, mine is mechanical advance and also is converted to digital, so I can't look at it now.  Have you tried isolating by plugging the vacuum line to the advance to eliminate that "action" that may be intermittent?  Good to know if you need to buy a new distributor and "use the same advance mechanism".  Do you, or someone else, have a good distributor to measure the diameter of the opposing lobs to see if yours are "worn down"?  The mystery continues...  Thanks for sharing.

[GunnersWillys]

Epilogue:  Going into this, we probably all knew this issue would be caused by something simple.  And, either I would overlook something obvious, or would have caused the problem by some sort of trivial mistake.  Or both.

Well, it was both, or maybe both, you can judge. 

I was on the verge of ordering a new distributor this morning, so I had a chat with Carl Walck.  We ran through the symptoms and what I'd done so far.  He pretty much agreed it was distributor related, but since the points wouldn't gap correctly he suggested I ream out the mount to allow more movement.  I did so and am now able to set the points at .020.  But, no real change in performance.

But something else he said got me thinking. He asked if the extra stainless spring for the points was in place, as the fact that it would miss at high rev suggested the points opening and closing could not keep up with the accelerating distributor cam.  So I took another look at a spare set.  Having followed the pattern for the points that were already in the distributor, I had placed the stainless spring OVER the copper spring, not under it.  It needed to go under!  Under, the pressure on the cam is much stronger.  A few seconds of tinkering and I figured out how it locked in, reinstalled them, and bingo!  Winner winner chicken dinner!  I have full acceleration, no more miss, and the engine runs like it should!

I still had the solid jumper wire from the points to the coil.  I'd previously removed the terminal post that feeds through the side of the distributor housing.  I reassembled as original, and no spark.  I finally just put back the jumper, and the engine is back to normal.  I need to fill in around the wire.  If anyone has any suggestions of the best way to do so, pipe up please.

I reset the timing slightly, seems perfect now.

It still doesn't want to start cold, but fires right up now when warm.  I'll drive it as much as possible over the next week or so to make sure I'm not missing something.  But after multiple pretty aggressive accelerations this afternoon, it is holding true.

Now on to 3 different oil leaks and very loose steering.  Thanks to everyone for their help! 

[Rus Curtis]

Sounds like a good reason to go drive!  Congrats!

[SteveKfl]

Yeah, I love a good ending, and an inexpensive solution too.  Congrats!  Can you use a small grommet or "liquid electrical tape" to fill the hole and insulate the wire from rubbing the metal?   Happy motoring!